In general, an electrical charge is generated by contact or friction in the inside of the surface of a material. In particular, in a case where the material is an electrical insulator such as chemical fibers or plastics, an electrical charge which is generated at the surface of the material accumulates without leakage from the surface of the material. The electrical charge accumulated at the surface thereof causes various problems in manufacturing processes or use of the material, since the electrical charge causes phenomena such as adhesion of dust, sticking of dust, repulsion, electric shock, discharge or the like. Accordingly, up to now, in order to leak smoothly an electrical charge which is generated at the surface of a material without accumulation, many methods for providing antistatic properties to a material have been proposed.
For example, an anti-reflection film is provided at the surface of a display or window for the purpose of preventing reflection of light, and adhesion of dust to the surface of the anti-reflection film is regarded as a problem. Accordingly, for example, in techniques which are described in Patent Documents 1 and 2, a method is proposed wherein antistatic properties are provided volumetrically by adding metal oxide particles having conductivity such as tin oxide, indium oxide, aluminium oxide, zinc oxide or the like in a hard coat layer of a film wherein plural layers are laminated.
Furthermore, for example, with respect to a packaging material used for food, when contents such as a fine powder or thin material (for example, shavings of dried bonito, flour, curry powder, a mixture of red pepper and other spices, furikake, tororo konbu, powder medicine or the like) is filled in a packaging material, the fine powder or thin material adheres to a sealing part due to static electricity, and causes insufficient sealing. Furthermore, when unsealing is performed to take out the contents, problems are caused wherein the contents adhere to a packaging material and it is difficult to take out the contents. Furthermore, adhesion of dust to an exterior package causes poor appearance. Accordingly, for example, a technique described in Patent Document 3 proposes a method wherein a layer including a surface-active agent such as a quaternary ammonium salt or the like is introduced in a packaging material which is a laminate, so that antistatic properties are provided to the laminate by adsorbing atmospheric moisture due to the layer.
Furthermore, for example, with respect to a packaging material for industrial materials, when electronic equipment or the like is packed, breakage of the contents caused by electrostatic charge or discharge is problematic. Therefore, for example, in a technique described in Patent Document 4, a metal thin film such as an Al-metallized film, an Al foil-laminated film or the like, which is excellent in conductivity, is used.